INTER192

INTER192 Element Description

INTER192 is a 2D four-node linear interface element used for 2D structural assembly modeling. When used with 2D linear structural elements (such as PLANE182), INTER192 simulates gasket joints. The element can be used either as a plane element (plane stress or plane strain) or as an axisymmetric element. It is defined by four nodes having two degrees of freedom at each node: translations in the nodal x and y directions.

See Gasket Material and INTER192 in the Mechanical APDL Theory Reference for more details about this element.

Also see Gasket Joints Simulation in the Structural Analysis Guide for more information about the gasket capability in Mechanical APDL.

Figure 192.1: INTER192 Geometry

INTER192 Input Data

The element geometry, node locations, connectivity, and the nodal coordinate system are shown in Figure 192.1: INTER192 Geometry. The element geometry is defined by 4 nodes, which form bottom and top lines of the element. The bottom line is defined by nodes I, J; and the top line is defined by nodes K, L. The element connectivity is defined as I, J, K, L. This element has 2 integration points. The Gauss integration scheme is used for the numerical integration.

Temperatures may be input as element body loads at the nodes. The node I temperature T(I), defaults to TUNIF. If all other temperatures are unspecified, they default to T(I). For any other input pattern, unspecified temperatures default to TUNIF.

Input the nodal forces, if any, per unit of depth for a plane analysis (except for KEYOPT(3) = 3) and on a full 360° basis for an axisymmetric analysis.

By default, the element is capable of both through-thickness and transverse shear deformations (KEYOPT(2) = 1). The inclusion of transverse shear stiffness is generally required when the interfaces between the gasket and the mating parts are modeled as sliding contact. However, if the interfaces are modeled with a matching mesh method (that is, with coincident nodes), Ansys, Inc. recommends using through-thickness deformation only (KEYOPT(2) = 0) to avoid unnecessary in-plane interaction between the gasket and the mating parts.

The following table summarizes the element input. See the Element Input section in the Element Reference for a general description of element input.

INTER192 Input Summary

Nodes

I, J, K, L

Degrees of Freedom

UX, UY

Real Constants

None, if KEYOPT(3) = 0, 1, or 2

THK - Plane stress with thickness, if KEYOPT(3) = 3

Material Properties

TB command: Gasket material

MP command: ALPX (or CTEX or THSX), BETD, DMPR, DMPS

Body Loads

Temperatures --: T(I), T(J), T(K), T(L)

Special Features

Linear perturbation

KEYOPT(2)

Element deformation:

0 --: Through-thickness deformation only
1 --: Through-thickness and transverse shear deformation (default)

KEYOPT(3)

Element behavior:

0 --: Plane stress
1 --: Axisymmetric
2 --: Plane strain (Z strain = 0.0)
3 --: Plane stress with thickness (THK) real constant input

KEYOPT(8)

Element component quantity output:

0 --: Gasket quantities are output (GKD, GKD, GKI, and GKTH) (default)
1 --: Standard stresses and strains are output (including S, EPEL, and EPTH )

INTER192 Output Data

The solution output associated with the element is in two forms:

Nodal items such as nodal displacements are included in the overall nodal solution.
Element items such as stresses and closures are element outputs as shown in Table 192.1: INTER192 Element Output Definitions.

The output directions for element items are parallel to the local element coordinate system based on the element midplane as illustrated in Figure 192.2: INTER192 Stress Output. See Gasket Material in the Mechanical APDL Theory Reference for details.

A general description of solution output is given in Solution Output. See the Basic Analysis Guide for ways to review results.

Figure 192.2: INTER192 Stress Output

The Element Output Definitions table uses the following notation:

A colon (:) in the Name column indicates that the item can be accessed by the Component Name method (ESOL). The O column indicates the availability of the items in the file Jobname.out. The R column indicates the availability of the items in the results file.

In either the O or R columns, “Y” indicates that the item is always available, a number refers to a table footnote that describes when the item is conditionally available, and “-” indicates that the item is not available.

Table 192.1: INTER192 Element Output Definitions

Name	Definition	O	R
EL	Element number	-	Y
NODES	Node connectivity - I, J, K, L	-	Y
MAT	Material number	-	Y
TEMP	Temperatures T(I), T(J), T(K), T(L)	-	Y
GKS:X, (XY)	X - Normal stress (also gasket pressure) XY - Transverse shear stress	Y	Y
GKD:X, (XY)	X - Total closure XY - Relative transverse shear deformation (, where is the transverse shear strain, and is the gasket thickness.	Y	Y
GKDI:X, (XY)	Total inelastic closure	Y	Y
GKTH:X, (XY)	Thermal closure	Y	Y
S:X, Y, Z, XY	Stresses (SZ = 0.0 for plane stress elements)	-	1
S:INT	Stress intensity	-	1
S:EQV	Equivalent stress	-	1
EPEL:X, Y, Z, XY	Elastic strains	-	1
EPEL:EQV	Equivalent elastic strain	-	1
EPTH:X, Y, Z, XY	Thermal strains	-	1
EPTH:EQV	Equivalent thermal strain	-	1
SEND:ELASTIC	Strain energy densities	-	1

To save these results to the .rst file, set KEYOPT(8) = 1.

INTER192 Assumptions and Restrictions

This element is not supported for initial stress.
Pressure as a type of surface load on element faces is not supported by this element.
This element is based on the local coordinate system; therefore, setting an element coordinate system attribute pointer (ESYS) is not supported.

INTER192 Product Restrictions

There are no product-specific restrictions for this element.